Currently, a fuser unit is used in an image forming apparatus of an electrophotographic type and includes a cylindrical fixing belt, a heater disposed at an inside of the fixing belt and generating radiation heat, a nip member slidingly contacting an inner periphery of the fixing belt and a reflection plate configured to cover the heater and reflecting the radiation heat toward the nip member (for example, refer to JP-A-2011-95534).
Specifically, the reflection plate continuously contacts the nip member over a substantial entire width in a longitudinal direction thereof.
However, according to the above art, the heat of the nip member escapes to the reflection plate, so that it is difficult to efficiently heat the nip member.
Accordingly, this disclosure provides at least a fuser unit capable of improving heating efficiency of a nip member.
With taking into consideration the above, a fuser unit of a first aspect of disclosure, which heat-fixes a developer image transferred on a recording sheet while moving the recording sheet in a predetermined direction, the fuser unit comprises: a cylindrical member having flexibility; a heat generation member that is arranged at an inside of the cylindrical member and generates radiation heat; a nip member that slidingly contacts an inner periphery of the cylindrical member; a reflection plate that contacts the nip member, is configured to cover the heat generation member and reflects the radiation heat toward the nip member, and a backup member that forms a nip region by nipping the cylindrical member between the nip member and the backup member. In the above fuser unit, the nip member and the reflection plate intermittently contact each other in an axial direction of the cylindrical member within an image forming width.
Further, another fuser unit of a first aspect of disclosure, which heat-fixes a developer image transferred on a recording sheet while moving the recording sheet in a predetermined direction, the fuser unit comprises: a cylindrical member having flexibility; a heat generation member that is arranged at an inside of the cylindrical member and generates radiation heat; a nip member that slidingly contacts an inner periphery of the cylindrical member; a reflection plate that contacts the nip member, is configured to cover the heat generation member and reflects the radiation heat toward the nip member; and a backup member that forms a nip region by nipping the cylindrical member between the nip member and the backup member. In the above another fuser unit, at least one of the nip member and the reflection plate has a contact part that contacts the other of the nip member and the reflection plate over an image forming width, and at least a portion of the contact part is cut out within the image forming width.
Accordingly, since the nip member and the reflection plate intermittently contact each other in the axial direction of the cylindrical member within the image forming width and then the escape of the heat from the nip member to the reflection plate is reduced, it is possible to improve the efficiency of the reflection plate reflecting the radiation heat.
A fuser unit of a second aspect of disclosure, which heat-fixes a developer image transferred on a recording sheet while moving the recording sheet in a predetermined direction, the fuser unit comprises: a cylindrical member having flexibility; a heat generation member that is arranged at an inside of the cylindrical member and generates radiation heat; a nip member that slidingly contacts an inner periphery of the cylindrical member; a reflection plate having a substantial U shape that is opened at a side facing the nip member so as to cover the heat generation member, as viewed from an axial direction of the cylindrical member; a backup member that forms a nip region by nipping the cylindrical member between the nip member and the backup member, and a stay having a substantial U shape that is opened at a side facing the nip member so as to cover the reflection plate, as viewed from the axial direction, the stay supporting the reflection plate from an opposite side to the backup member, wherein at least one of a pair of wall parts arranged at both sides of the reflection plate in the predetermined direction is inclined so that an inner surface thereof faces the nip member.
Accordingly, since the inner surface of the reflection plate is configured to face the nip member, it is possible to improve the efficiency of the reflection plate reflecting the radiation heat.